Device for supplying a free diver with air by means of a compressed-air breathing app



Oct. 24, 1961 R. WELLENSTEIN EI'AL 3,005,453

DEVICE FOR SUPPLYING A FREE DIVER WITH AIR BY MEANS OF A COMPRESSED-AIR BREATHING APPARATUS Filed March 15, 1957 l4 5 IO I3 INVENTORS I ROBERT WELLENSTEIN CHRISTIAN RACKERSEDER ATTORNEYS its This invention relates to a subaqueous breathing apparatus and more particularly to a subaqueous breathing apparatus of the compressed air type.

Known subaqueous breathing apparatus are either perated on oxygen or compressed air supply bottles or both. These known apparatus are only adapted to be used for depths up to 60 feet, as the oxygen or the carbon dioxide becomes toxicating to the human organism at a total pressure of more than 42.6 psi.

The known types of subaqueous breathing apparatus of the compressed air type are afilicted with the drawback that the supply tank must be rather voluminous, as all of the exhaled air is discharged into the water at each exhalation. It is a well known fact that the lungs will only absorb a minor portion of the oxygen contained in the air and, thus, a valuable amount of oxygen is wasted in discharging all of the exhaled air.

In order to overcome this drawback, it has been proposed to provide a breathing apparatus by which air with an enriched oxygen content is breathed and a percentage of oxygen in the expired gases is utilized at a given depth for reinhalation. For this purpose, the apparatus is provided with means constantly providing oxygen to the diver at a predetermined rate.

This known breathing apparatus is afilicted with the drawback that in case of failure of the breathing valve, the user is no longer supplied with fresh breathing gas. Another drawback resides in the fact that the diver must consistently breathe deeply to insure that he will not sufiier a nitrogen narcosis.

Broadly, it is the object of this invention to provide a breathing apparatus which eliminates the above drawbacks. The principal object of the invention is to supply a breathing apparatus which will always supply the diver with the necesary minimum of oxygen, regardless of whether his inhalation is deep or shallow, and regardless of whether the breathing valve should fail to op erate correctly. Another object of the invention is to provide a breathing apparatus in which the ratio between the inhaled volume of air and the volume of; a r supplied during the same period of time from the supply tank is automatically controlled by the water pressure in such a way that the fresh air fed from the supply tank decreases as the depth of diving increases.

The invention will be explained in detail with reference to the accompanying drawings which show by way of example some embodiments of the apparatus according to the invention, and in which:

FIG. 1 shows a subaqueous breathing apparatus according to the invention in a schematical manner;

FIG. 2 shows another embodiment of a breathing apparatus in accord with the invention.

In the figures, corresponding parts are designated with equal reference numerals:

As shown in FIG. 1, a compressed-air tank 1 provided with a closure means 2 communicates via a pressure reduction valve 3 and a low-pressure line 4 with a housing 5. Within the housing 5 a diaphragm 6 is arranged dividing the housing into an upper and a lower compartment 5a and 5b. The lower pressure line 4 extends into the upper compartment 5a of housing 5 Patented Oct. 24, 1961 and carries near its end an inhaling valve 7 cooperating with the diaphragm 6. The lower compartment 5b is provided with apertures 8 serving as an inlet for the surrounding water. The upper compartment 5a of the housing 5 communicates via an air supply line 9 with a mouthpiece 11, and air supply line 9 communicates with a variable volume storage container 10 which may consist of any elastic material, e.g. rubber, and which is inflatable and deflatable in dependence on the pressure of the surrounding water and the air within the lungs. The exhaling line 12 is provided with an exhaling valve 13 set to open at a predetermined overpressure in line 12 relative to the surrounding water pressure.

An absorption chamber.14- containing a C0 retaining chemical is arranged within the upper compartment 5a and communicates at the one hand with the exhaling line 12 and on the other hand with the upper compartment 5a.

The mouthpiece 11 is provided with an inlet valve 15 and an outlet valve 16, the inlet valve 15 restricting the flow of air to a single direction in the supply line 9 and opening upon inhaling and closing upon exhaling while the outlet valve 16 is arranged in the outlet opening of the exhaling line 12 opening upon exhaling and closing upon inhaling.

An adjustable valve 17 is arranged at the end of the low-pressure line 4 having an opening 18 communicating with the upper compartment 5a of housing 5. This adjustable valve may be regulated manually to constantly feed a given amount of air from the supply tank 1 to the supply line 9 and thus to the variable volume storage container 10.

The apparatus operates as follows: After the closure means 2 has been opened, high-pressure air is fed to the reducing valve 3 and low-pressure air is fed tothe low-pressure line 4 and to the inlet valve 7. The space 5a above the diaphragm 6 communicates with lines 9 and 12 to the pressure of the lungs, while the space 5b below the diaphragm 6 is exposed to the water pressure. As long asboth pressures are equal, the valve 7 is closed. When inhaling, a lower pressure is formed above th diaphragm 6 to thereby open the valve 7 whereby air may enter the line 9. It may be assumed that at that very moment the variable volume storage container 10 is deflated to its smallest volume. The exhaling valve 13 in line 12 is closed by a spring. When exhaling, inlet valve 15 of the mouthpiece 11 closes and outletyalve 16 opens and the exhaled air will flow via line 12 and absorption chamberhlt to the-deflated variable volume storage container 10, inflating it. As soon as the exhaling pressure of the lungs becomes higher than the combined pressure of the water and the spring acting on the exhaling valve 13, due to the fact that the inflated volume of container 10 is smaller than the capacity of the lungs, the exhaling valve 13 will open sothat the rest of the exhaled air will be discharged into the water. The dotted line arrow indicates the path of the exhaled air.

Upon initial inhaling, valve 16 of the mouthpiece 11 closes and valve 15 opens while the inhaling valve 7 remains closed until the variable volume container 10 has been emptied. Upon further inhaling, an underpressure relative to the water pressure is formed in the upper compartment 5a of the housing 5 causing the diaphragm 6 to deflect upwardly, thereby opening the inhaling valve 7, so that the rest of the inhaled air will be supplied from the supply tank 1.

The constant feed valve 17, which is of great importance, serves the following purpose. By suitably adjusting the valve 17, the diver will continuously be supplied with the minimum of fresh air from the supply tank 1 that is required, e.g. when being motionless in a certain depth due to an accident, such as fainting of the diver, failure of the inhaling valve 7 or any other reason where he is breathing very lightly. The constant feeding valve 17 aifords another important advantage in that upon the diver ceasing to breathe, a pressure higher than the water pressure will be built up in the system which will open the exhaling valve 13. The rising air bubbles will greatly facilitate finding the location of the diver. Another advantage of the constant feed valve resides in the fact that the difiiculty of determining the correct size of the variable volume container with respect to different inhalation requirements of difierent divers is overcome. If the diver suddenly breathes very weakly, the container 10 will not be emptied and, consequently, the valve 7 will not open to feed a fresh supply of air. This would lead to a catastrophe but for the provision of the constant feed valve 7.

The variable volume container 10 may be constructed in any suitable manner, preferably, however, a rubber bag is used having a maximum volume which may be regulated by using an adjustable network surrounding it.

The embodiment of the breathing apparatus shown in FIG. 2 is similar to that one just described and operates in the same manner. The only difference existing between the two embodiments is that in FIG. 2 the variable volume storage container 10 is provided with an inner variable volume bag 20 having a valve 22 on the outside of container 10. The bag 26' may be inflated with air forming a compensating means for varying the total volume of container 10 independence on the Water pressure and the pressure of the lungs, and does not change its maximum volume. The volume of bag 20', however, being subjected to the water pressure, will vary its volume in dependence of the water pressure, thus increasing the maxi-mum volume of container 10 on increasing water pressure. This means that less air is supplied from the tank the deeper the diver goes. This is very desirable, as in growing depths, the amount of oxy gen inhaled by the diver increases due to the compression of the air. In a depth of 90 feet, for instance, the amount of oxygen fed to the diver will be fourfold as compared to depths close to the surface of the water.

While two forms of the invention have been illustrated in the drawings and described above, it will be understood that the invention may be changed without departing from the scope of the invention.

What we claim is:

1. In a subaqueous breathing apparatus, comprising a compressed-air supply tank, a pressure reduction valve connecting said supply tank with a low pressure line, a mouthpiece communicating with an intermittingly operating inhaling valve regulating air flow through said low-pressure line and being controlled in response to the pressure in the lungs of the user and the surrounding water pressure, a variable volume storage means for lowpressure breathing air in communication with the mouthpiece adapted to receive and store a portion of the air exhaled by the user for reuse upon inhaling, a chemical absorption chamber interposed between said mouthpiece and said variable volume storage means during exhaling of the user, an exhalation valve communicating with said mouthpiece upon exhalation adapted to release exhaled air to the surrounding water upon attaining a predetermined pressure within said variable volume storage means, and an adjustable valve in communication with said low-pressure line and said mouthpiece adapted to continuously supply the mouthpiece with air independently of said inhaling valve.

2. In a subaqueous breathing apparatus, comprising a compressed-air supply tank, a pressure reduction valve connecting said supply tank with a low-pressure line, a mouthpiece communicating with an intermittingly operating inhaling valve regulating air flow through said lowpressure line and being controlled in response to the pressure in the lungs of the user and the surrounding water pressure, a variable volume storage means for low pressure breathing air in communication with the mouthpiece adapted to receive and store a portion of the air exhaled by the user for reuse upon inhaling including compensating means adapted to automatically increase the volume of said storage means as the surrounding water'pressure increases, a chemical absorption chamber interposed between said mouthpiece and said variable volume. storage means during exhaling of the user, an exhalation valve communicating with said mouthpiece upon exhalation adapted to release exhaled air to the surrounding water upon attaining a predetermined pressure within said variable volume storage means, and an adjustable valve in communication with said low-pressure line and said mouthpiece adapted to continuously supply the mouthpiece with air independently of said inhaling valve.

3. A subaqueous breathing apparatus as in claim 2, wherein said storage means comprises a first deformable container, and said compensating means comprises a gas filled second deformable container within said first container.

References Cited in the file of this patent UNITED STATES PATENTS 2,732,840 De Sanctis Jan. 31, 1956 2,788,001 Brown Apr. 9, 1957 FOREIGN PATENTS 1,130,272 France Sept. 24, 1956 

